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Cyclosporine A (CsA) is associated with the development of cardiovascular toxicity in transplant patients but can exert myocardial protection against ischemia/reperfusion damages. We examined in a rat model of chronic CsA administration whether subtle variations in the NO pathway could account for these opposite effects. CsA treatment rapidly led to an increase in myocardial Hsp90 expression promoting the recruitment of Akt and calcineurin, thereby promoting eNOS activation through Ser1177 phosphorylation and Thr495 dephosphorylation, respectively. This was associated with an increase in myocardial VEGF expression and led to anti-apoptotic effects in isolated cardiac myocytes. Upon longer CsA exposure, cardiac toxicity developed, as documented by the infiltration of connective tissue and the increase in iNOS expression. These later effects were associated with a dramatic decrease in the abundance and scaffold function of Hsp90, thereby unraveling the key role of Hsp90 in governing CsA effects.

Abnormal architecture of the tumor blood network, as well as heterogeneous erythrocyte flow, leads to temporal fluctuations in tissue oxygen tension exposing tumor and stromal cells to cycling hypoxia. Inflammation is another feature of tumor microenvironment and is considered as a new enabling characteristic of tumor progression. As cycling hypoxia is known to participate in tumor aggressiveness, the purpose of this study was to evaluate its role in tumor-promoting inflammation. Firstly, we assessed the impact of cycling hypoxia in vitro on endothelial inflammatory response induced by tumor necrosis factor α. Results showed that endothelial cells exposed to cycling hypoxia displayed an amplified proinflammatory phenotype, characterized by an increased expression of inflammatory cytokines, namely, interleukin (IL)-6 and IL-8; by an increased expression of adhesion molecules, in particular intercellular adhesion molecule-1 (ICAM-1); and consequently by an increase in THP-1 monocyte adhesion. This exacerbation of endothelial inflammatory phenotype occurs through nuclear factor-κB overactivation. Secondly, the role of cycling hypoxia was studied on overall tumor inflammation in vivo in tumor-bearing mice. Results showed that cycling hypoxia led to an enhanced inflammation in tumors as prostaglandin-endoperoxide synthase 2 (PTGS2), IL-6, CXCL1 (C-X-C motif ligand 1), and macrophage inflammatory protein 2 (murine IL-8 functional homologs) mRNA expression was increased and as a higher leukocyte infiltration was evidenced. Furthermore, cycling hypoxia-specific inflammatory phenotype, characterized by a simultaneous (baculoviral inhibitor of apoptosis repeat-containing 5)(low)/PTGS2(high)/ICAM-1(high)/IL-6(high)/IL-8(high) expression, is associated with a poor prognosis in human colon cancer. This new phenotype could thus be used in clinic to more precisely define prognosis for colon cancer patients. In conclusion, our findings evidenced for the first time the involvement of cycling hypoxia in tumor-promoting inflammation amplification.

A significant phenotypical variability is observed in autosomal dominant polycystic kidney disease (ADPKD). ADPKD is associated with altered endothelial-dependent vasodilation and decreased vascular production of nitric oxide (NO). Thus, ENOS, the gene coding for the endothelial nitric oxide synthase (eNOS), could have a modifier effect in ADPKD. In order to test this hypothesis, we genotyped 173 unrelated ADPKD patients from Belgium and the north of France for the Glu298Asp, intron 4 VNTR and T-786C polymorphisms of ENOS and looked for their influence on the age at end-stage renal disease (ESRD). In males (n = 93), the Glu298Asp polymorphism was associated with a lower age at ESRD (Glu/Asp + Asp/Asp: 49.0 +/- 1.2 years, n = 53; Glu/Glu: 53.5 +/- 1.5 years, n = 40; simple regression, P = 0.02; multiple regression, P = 0.006). This effect was confirmed in a subset of males linked to PKD1 and reaching ESRD before age 45, and by a cumulative renal survival analysis in PKD1-linked families. Further studies demonstrated that NO synthase (NOS) activity was decreased in renal artery samples from ADPKD males harbouring the Asp298 allele, in association with post-translational modifications and partial cleavage of eNOS. No significant effect of the other polymorphisms was found in males, and no polymorphism influenced the age at ESRD in females. In conclusion, the frequent Glu298Asp polymorphism of ENOS is associated with a 5 year lower mean age at ESRD in this subset of ADPKD males. This effect could be due to a decreased NOS activity and a partial cleavage of eNOS, leading to a further decrease in the vascular production of NO.

Because nitric oxide (NO) regulates cardiac and vessel contraction, we compared the expression and activity of the endothelial NO synthase (eNOS) and caveolin, which tonically inhibits eNOS in normal and hypertrophic cardiomyopathic hearts. NOS activity (l-[3H]citrulline formation), eNOS immunostaining, and caveolin abundance were measured in heart tissue of 23 mongrel dogs before and at 3 and 7 wk of perinephritic hypertension (PHT). Hemodynamic parameters in vivo and endothelial NO-dependent relaxation of macro- and coronary microvessels in vitro were assessed in the same animals. eNOS immunostaining and total calcium-dependent NOS activity decreased at 7 wk in all four heart cavities (in left ventricle, from 17.0 ± 1.3 to 0.2 ± 0.2 fmol · min−1 · mg protein−1, P < 0.001). Caveolin-1 and -3 also decreased in PHT dog hearts. Accordingly, basal vascular tone was preserved, but maximal endothelial NO-dependent relaxation was impaired in all vessels from 7-wk PHT dogs. The latter had preserved systolic function but impaired diastolic relaxation [relaxation time constant ( T 1), 25.1 ± 0.9 vs. 22.0 ± 1 ms in controls; P < 0.05]. Peripheral infusion of the NOS inhibitor N G -nitro-l-arginine methyl ester increased mean aortic pressure in both groups and reduced diastolic ( T 1, 31.9 ± 1.4 ms) and systolic function in PHT dogs (DP40, 47.5 ± 2.5 vs. 59.4 ± 3.8 s−1 in control animals). In conclusion, both eNOS and caveolin proteins are decreased in the hypertrophic hearts of PHT dogs. This is associated with altered maximal (but not basal) vascular relaxation and impaired diastolic function. Further degradation of cardiac function after NOS inhibition suggests a critical role of residual NOS activity, probably supported by the concurrent downregulation of caveolin.

1. The tissue-protective effects of calcium channel blockers in hypertension are not well dissociated from their effect on systolic blood pressure (SBP). We have previously shown that lacidipine, a dihydropyridine-type calcium antagonist, reduced the cardiac hypertrophy and the cardiac endothelin-1 (ET-1) gene overexpression occurring in salt-loaded stroke-prone spontaneously hypertensive rats (SL-SHRSP), an effect occurring without systolic blood pressure (SBP) change. In the present study, we have examined whether this action was dose-related and if it could be associated with ET receptor changes. The action of lacidipine was also examined in control SHRSP and in Wistar Kyoto rats (WKY). 2. The daily dose of 0.3 mg kg-1 lacidipine which did not lower SBP but significantly prevented ventricle hypertrophy and cardiac preproET-1-mRNA expression in SL-SHRSP was inactive in control SHRSP. With the higher dose of lacidipine (1 mg kg-1 day-1), we observed a further reduction of cardiac hypertrophy and of ET-1 gene expression in SL-SHRSP and a significant effect on those parameters in control SHRSP but only a small reduction of SBP in both groups. 3. In WKY, salt loading did not induce change in SBP or increase of cardiac ET-1 gene expression and ventricle mass. In these normotensive rats, lacidipine (1 mg kg-1 day-1) did not modulate the basal preproET-1-mRNA expression and did not affect SBP or heart weight. 4. The maximum binding capacity (Bmax) and the dissociation constant (KD) of [125I]-ET-1 binding and the relative proportion of low- and high-affinity binding sites for ET-3 were not significantly affected by salt loading or lacidipine treatment in SHRSP. 5. These results show that lacidipine exerted a dose-related inhibition of ventricle hypertrophy and preproET-1-mRNA expression in SHRSP and indicate that this effect was unrelated to SBP changes. The dose-dependency of this inhibition suggests that salt-induced cardiac hypertrophy could be related to ET-1 gene overexpression. The results further show that ET receptor changes are not involved in the pathophysiological process studied here.

In order to develop a computer-assisted process optimization of In1-x Ga x As y P1-y metalorganic chemical vapor deposition (MOCVD), the kinetics of GaAs growth was studied as the first step. For the accumulation of reaction data of source materials, the decomposition rates of trimethylgallium (TMGa) and tertiarybutylarsine (TBAs) were studied using a flow tube reactor and a Fourier transform infrared spectrometer (FT-IR). Special attention was paid to the effect of TBAs concentration on the decomposition rates of TMGa. The GaAs growth rate profile in a commercial MOCVD reactor was analyzed through both experiment and simulation. The profile was dependent on the gas velocity and total pressure. This dependency was explained by a reaction model which was deduced from the experimental observations: TMGa decomposes to a gas-phase intermediate which subsequently forms the GaAs film. The fluid dynamic calculations combined with this reaction model led to growth rate distributions which agreed well with the experimental data. The analysis revealed that the GaAs growth rate is limited by the gas-phase reactions of TMGa as well as the mass-transport of the intermediates, and that precise measurement of the reaction between TMGa and TBAs is essential for an accurate simulation.

A series of symmetrical Schiff base derivatives (L1-L7) were designed by a one-pot condensation reaction of various aldehyde/ketone compounds with hydrazine under mild conditions ( room temperature, 3 days), using ether as solvent and acetic acid as catalyst. The target products were characterized and analysed by H-1 and C-13 NMR, FT-IR and liquid chromatography mass spectrometry (LC/MS). Our research focuses on the identification of synthetically chemotherapeutic substances able to inhibit, delay, or reverse the process of carcinogenesis in several stages. The target compounds presenting two regions for SAR evaluation were screened for their activity toward MDA-MB-241 breast cancer cell proliferation for the first time. Compound (1E, 2E)-1,2-bis(1-(3-nitrophenyl)ethylidene) hydrazine (L6) showed significant inhibitory activity (IC50 = 7.08 mu g/mL).

Background In cardiovascular research, there is an increasing interest in high-field MRI to characterize cardiac anatomy and function in small rodents. However, data on reproducibility of the method are scarce. Our aim was to evaluate the intra-observer, inter-experiment and inter-observer variability of left ventricular (LV) mass and volumes measurements in mice using an 11.7T MRI scanner. Methods Seven 10 weeks-old C57Bl6J male mice were studied, including 4 animals with a surgical transverse aortic constriction in order to produce cardiac hypertrophy. 3 were sham (control) mice. During the entire procedure, animals were anaesthetized with Isoflurane 1-3%, in a temperature-controlled setting. Scan were retrospectively gated for electrocardiogram (ECG) and respiration. Imaging was performed on a 11.7 Tesla Bruker MR scanner. Cardiac scout images were obtained in the conventional planes with a tripilot sequence. A 2D cine FLASH sequence was applied to acquire a set of 7 contiguous short axis images covering the entire ventricles, perpendicular to the LV long axis. One day after the procedure, mice were scanned again under the same conditions. The LV systolic function was assessed from each stack of images by tracing epicardial and endocardial borders, including papillary muscles, on the Segment software (Medviso, Sweden). End-diastolic (EDV), end-systolic (ESV) and stroke volume (SV) were determined (µl). LV ejection fraction (EF, in %) and LV mass (mg) were subsequently deduced. One stack of images was analyzed twice by the same person, and once by an independent observer. Results Accurate quantitative data were obtained in all animals. The Table 1 lists the mean ± SD values and the Bland-Altman and Pearson analysis results. The best reproducibility was obtained for the measurements of LV mass and EDV, with a coefficient of variability (Cov) between 1.70 and 12%. More variation was found in ESV measurement (CoV 1-70-22.40%). Results for SV and EF were the less reproducible, with a CoV between 14.52 and 31.45%. The Pearson correlation coefficient indicates good correlation between all methods for all parameters (r square between 0.81 and 0.99), except for the SV, particularly in terms of inter-experiment reproducibility (r square =0.03). Conclusions In our hands, reproducibility was excellent for LV mass and EDV, good for ESV and EF to al esser extent, and more limited for the stroke volume, with a bad inter-observer correlation. This highlights the need to interpret our results by taking into account these limitations, focusing on more reproducible parameters when interpreting data.

IntroductionIn cardiovascular research, there has recently been an interest in ultra-high field MRI to characterize cardiac anatomy and function in rodents. However, reports on the accuracy of the method are scarce. The purpose of our work was to evaluate left ventricular (LV) systolic function in a mouse model of cardiac hypertrophy using an 11.7T MRI machine and to assess the validity of our results by comparing them with ex vivo measurements.Methods24 C57Bl/6J mice were studied, including 11 animals having undergone a surgical transverse aortic constriction (TAC) and 13 sham animals. Imaging was performed on a 11.7 Tesla Bruker MR scanner. The LV systolic function was assessed from a stack of 1mm thick short-axis views obtained with a FLASH-cine sequence covering the entire ventricles. Using a dedicated software (SegmentTM, Medviso, Sweden), the following volumes (μl) were determined: end-diastolic, end-systolic and stroke volumes. LV ejection fraction (in %) and LV mass (mg) were subsequently deduced. One week after, mice were sacrificed and their LV mass and tibial length (TL) were measured.ResultsAs expected, LV mass was significantly higher in the TAC group. When using the previously validated LV mass/tibial length ratio (LV/TL), sham mice showed a ratio of 4.65±0.09mg/mm and 3.83±0.11mg/mm for morphometric and MRI measurements respectively, and TAC mice showed a ratio of 6.50±0.40 and 5.39±0.28 respectively (p

Background: Surface-expressed Na+/K+-ATPase (NaK) has been suggested to function as a non-canonical cardiotonic steroid-binding receptor that activates multiple signaling cascades, especially in cancer cells. By contrast, the current study establishes a clear correlation between the IC50in vitro growth inhibitory concentration in human cancer cells and the Ki for the inhibition of activity of purified human α1β1 NaK.Methods: The in vitro growth inhibitory effects of seven cardiac glycosides including five cardenolides (ouabain, digoxin, digitoxin, gitoxin, uzarigenin-rhamnoside, and their respective aglycone forms) and two bufadienolides (gamabufotalin-rhamnoside and hellebrin, and their respective aglycone forms) were determined by means of the MTT colorimetric assay and hellebrigenin-induced cytotoxic effects were visualized by means of quantitative videomicroscopy. The binding affinity of ten of the 14 compounds under study was determined with respect to human α1β1, α2β1 and α3β1 NaK complexes. Lactate releases and oxygen consumption rates were also determined in cancer cells treated with these various cardiac glycosides.Results: Although cardiotonic steroid aglycones usually display weaker binding affinity and in vitro anticancer activity than the corresponding glycoside, the current study demonstrates that the hellebrin / hellebrigenin pair is at odds with respect to this rule. In addition, while some cardiac steroid glycosides (e.g. digoxin), but not the aglycones, display a higher binding affinity for the α2β1 and α3β1 than for the α1β1 complex, both hellebrin and its aglycone hellebrigenin display ~2-fold higher binding affinity for α1β1 than for the α2β1 and α3β1 complexes. Finally, the current study highlights a common feature for all cardiotonic steroids analyzed here, namely a dramatic reduction in the oxygen consumption rate in cardenolide- and bufadienolide-treated cells, reflecting a direct impact on mitochondrial oxidative phosphorylation.Conclusions: Altogether, these data show that the binding affinity of the bufadienolides and cardenolides under study is usually higher for the α2β1 and α3β1 than for the α1β1 NaK complex, excepted for hellebrin and its aglycone form, hellebrigenin, with hellebrigenin being as potent as hellebrin in inhibiting in vitro cancer cell growth. © 2013 Moreno Y Banuls et al. licensee BioMed Central Ltd., SCOPUS: ar.j, info:eu-repo/semantics/published